The present disclosure relates to a drive controller that controls a stop of a movable body driven by a drive part, an imaging apparatus and a drive control method.
For an autofocus function, an electrically-driven zoom function and a camera shake correction mechanism, an electromagnetic conversion motor using a coil and a magnet such as a stepping motor, a voice coil motor and a DC motor is often used. In the electromagnetic conversion motor, it is difficult to keep the position when energization of the motor is turned off. In particular, when the energization is suddenly turned OFF in the middle of high-speed drive, the motor is affected by inertia of a lens movable part and is stopped at a position past the position at which the energization is turned off. Therefore, generally from a viewpoint of saving power or the like, when turning off the energization, it may be necessary to turn off the energization only after the movable body is completely stopped after a stop is instructed.
In a stepping motor for instance, as disclosed in JP2006-158019A, after the end of microstep drive, a rotor is driven to make an excitation position of the rotor coincide with an excitation position of a stator, and then energization of the motor is turned off. This prevents the motor from stopping out of an originally intended position at which the motor should actually be stopped due to detent torque that the motor has.